Light irradiation molding apparatus and light irradiation molding method

ABSTRACT

A light irradiation molding apparatus includes a pair of rubber die units, which are formed of a rubber material having a property of transmitting light therethrough and form a cavity between facing sides which face each other, and a light irradiation device, which applies light to a particulate or solid thermoplastic resin arranged in the cavity through surfaces of a pair of the rubber die units. In the light irradiation molding apparatus a pair of the rubber die units are made to come close to each other while the thermoplastic resin arranged in the cavity is molten by the light applied from the light irradiation device, and a molded article of the thermoplastic resin is formed in the cavity having a reduced volume.

TECHNICAL FIELD

The present invention relates to a light irradiation molding apparatusfor forming a molded article by filling a thermoplastic resin in acavity formed by a pair of rubber die units having a property oftransmitting light therethrough, and irradiating the resin with light;and a light irradiation molding method.

BACKGROUND ART

As a method for obtaining a molded article having a predetermined shape,using a thermoplastic resin, there are generally various molding methodsincluding injection molding, blow molding, extrusion molding,press-molding, and the like.

Besides these general molding methods, for example, Patent Document 1discloses a method in which a thermoplastic resin is irradiated with anelectromagnetic wave having a wavelength range of 0.78 to 2 μm throughmolding dies when the molten thermoplastic resin is filled in a cavityin a molding die. According to the method, the thermoplastic resin isheated more strongly than the molding die formed of rubber, due to thedifferences in physical properties between the rubber forming themolding die and the thermoplastic resin.

In addition, for example, Patent Document 2 discloses that a particulatethermoplastic resin in a cavity in a rubber molding die is irradiatedwith an electromagnetic wave having a wavelength range of 0.78 to 2 μmto heat and melt this thermoplastic resin, and then a moltenthermoplastic resin is additionally filled in a space left in thecavity.

PRIOR ART DOCUMENTS Patent Documents

-   Patent Document 1: JP-A-2007-216447-   Patent Document 2: JP-A-2009-241455

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

According to Patent Document 1, however, an apparatus for previouslymelting pellets of thermoplastic resin in the state of a particle or asolid is necessary, because the thermoplastic resin which has beenpreviously molten is filled in the cavity in the molding die. Accordingto the Patent Document 2, the same apparatus as above is necessary, too,because the molten thermoplastic resin is additionally filled. Inaddition, when the thermoplastic resin is filled in a molten state, itis necessary to secure the extra thermoplastic resin, and thus it isdifficult to reduce the amount of the thermoplastic resin used.

The present invention has been made in view of the conventional problemsdescribed above, and it provides a light irradiation molding apparatusand a light irradiation molding method, which does not require theapparatus which previously melts a thermoplastic resin and introduces itinto a cavity, and is capable of forming a molded article using a smallamount of the thermoplastic resin.

Means for Solving the Problem

A first aspect of the present invention is a light irradiation moldingapparatus including a pair of rubber die units which are formed of arubber material having a property of transmitting light therethrough andform a cavity between facing sides which face each other, and a lightirradiation means for applying light to a particulate or solidthermoplastic resin arranged in the cavity through surfaces of a pair ofthe rubber die units, which is characterized in that a pair of therubber die units are constituted so that they are made to come close toeach other to reduce a volume of the cavity while the thermoplasticresin arranged in the cavity is molten by the light emitted from thelight irradiation means.

A second aspect is a light irradiation molding method characterized byusing a pair of rubber die units which are formed of a rubber materialhaving a property of transmitting light therethrough and form a cavitybetween facing sides which face each other, and a light irradiationmeans for applying light to a particulate or solid thermoplastic resinarranged in the cavity through surfaces of a pair of the rubber dieunits; making a pair of the rubber die units to come close to each otherto reduce a volume of the cavity, while the thermoplastic resin arrangedin the cavity is molten by applying light emitted from the lightirradiation means; and forming a molded article of the thermoplasticresin in the cavity having a reduced volume.

Effect of the Invention

According to the light irradiation molding apparatus and the lightirradiation molding method described above, a cavity having a largervolume than that of a molded article to be formed is formed between apair of rubber die units, and the molded article is obtained while thevolume of the cavity is reduced, when a particulate or solidthermoplastic resin is molten.

The particulate or solid thermoplastic resin is arranged in the cavitybetween a pair of the rubber die units, and light is applied to thesurfaces of a pair of the rubber die units by using the lightirradiation means. At this time, much light penetrates the rubber dieunits and is absorbed in the thermoplastic resin. The thermoplasticresin is heated and molten by this mechanism. At this time, a pair ofthe rubber die units are made to come close to each other, therebyreducing the volume of the cavity, and as a result, the moltenthermoplastic resin fills up the whole of the cavity.

As described above, a molded article of the thermoplastic resin can beformed in the cavity having the reduced volume. The molded article canbe taken out by releasing a pair of the rubber die units after thearticle is cooled and solidified.

According to the light irradiation molding apparatus and the lightirradiation molding method described above, therefore, an apparatus forpreviously melting the thermoplastic resin and pouring it into thecavity is not required, and the molded article can be formed of a smallamount of the thermoplastic resin.

When the solid thermoplastic resin is used, it is possible that thesolid thermoplastic resin is arranged in a part of the cavity and aparticulate thermoplastic resin is arranged in a remaining part of thecavity.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 An illustrative drawing showing a state in which a thermoplasticresin is arranged in a cavity between a pair of rubber die units whichare located in an initial position in Example 1, as a frontcross-sectional view.

FIG. 2 An illustrative drawing showing a state in which a thermoplasticresin is arranged in a cavity between a pair of rubber die units whichare located in an initial position in Example 1, as a lateralcross-sectional view.

FIG. 3 An illustrative drawing showing a configuration of suction portand multiple suction gates in one side rubber die unit in Example 1, asa top cross-sectional view.

FIG. 4 An illustrative drawing showing a state in which a thermoplasticresin receives light irradiation and is molten, and a pair of the rubberdie units are made to come close slightly to each other in Example 1, asa front cross-sectional view.

FIG. 5 An illustrative drawing showing a state in which a thermoplasticresin receives light irradiation and is molten, and a pair of the rubberdie units are made to come closest to each other in Example 1, as afront cross-sectional view.

FIG. 6 An illustrative drawing showing a molded article in Example 1 asa front cross-sectional view.

FIG. 7 A graph showing light transmittances of silicone rubbers inExample 1.

FIG. 8 An illustrative drawing showing a state in which a thermoplasticresin is arranged in a cavity between another pair of rubber die units,different from the above, in Example 1, as a lateral cross-sectionalview.

FIG. 9 An illustrative drawing showing a pair of rubber die units in aninitial position in Example 2, as a front sectional-view.

FIG. 10 An illustrative drawing showing a state in which a thermoplasticresin receives light irradiation and is molten, and a pair of rubber dieunits are made to come close partially and sequentially to each other inExample 2, as a front cross-sectional view.

MODE FOR CARRYING OUT THE INVENTION

Preferable embodiments of the light irradiation molding apparatus andthe light irradiation molding method described above will be explained.

The thermoplastic resin is used in the state of a particle or a solid.Here, “particle” means a spherical shape, a cylindrical shape, and anindeterminate shape in a crushed product. “Solid” refers to a plate, abar or a linear state.

The particulate or solid thermoplastic resin can be appropriatelyselected depending on a shape of a desired molded article. Theparticulate or solid thermoplastic resin may be used as a mixture of twoor more resins having a different shape.

When the thermoplastic resin is in the state of a particle, the particlesize of the thermoplastic resin which can be used depends on a thicknessof a molded article, i.e., a width of a cavity, and the particle size ofthe thermoplastic resin can be within a range of 1 to 3000 μm. Theparticle size of the thermoplastic resin can be preferably within arange of 50 to 3000 μm, more preferably within a range of 200 to 2500μm.

When the thermoplastic resin has an average particle size within therange described above and includes small particles of the thermoplasticresin having a particle size of 1 to 100 μm, such thermoplastic resin issometimes preferable to be filled into the cavity. The particles have abulk density of preferably 0.4 or more, more preferably 0.45 or more,further more preferably 0.5 or more.

The light irradiation means preferably generates light including awavelength range of 0.78 to 2 μm. In this case, a larger amount of lightcan be easily absorbed in the thermoplastic resin in the cavity than inthe rubber die units, and the thermoplastic resin can be more positivelyheated and molten than the rubber die units.

The lights (electromagnetic waves), which are applied to thethermoplastic resin through the rubber die units, may have not onlylight having a wavelength with a range of 0.78 to 2 μm but also lighthaving a wavelength with a range other than the above. In this case, thelights, which are applied to the thermoplastic resin through the rubberdie units, preferably include a larger amount of light having awavelength with a range of 0.78 to 2 μm than light having a wavelengthwith a range other than the above.

As the thermoplastic resin used for forming the molded article(hereinafter may be referred to as only a “thermoplastic resin”), resinscapable of absorbing lights (electromagnetic waves) thereby promotingheating can be used.

This thermoplastic resin is not particularly limited so long as it hasthermoplasticity, and includes rubber-reinforced styrene resins such asan ABS resin (acrylonitrile butadiene styrene resin), an ASA resin(acrylate styrene acrylonitrile resins) and an AES resin (acrylonitrileethylene-propylene-diene styrene resin); styrene resins such aspolystyrene, a styrene-acrylonitrile copolymer, a styrene-maleicanhydride copolymer, and a (meth)acrylic ester-styrene copolymer; olefinresins such as polyethylene and polypropylene; cyclic olefin resins,acrylic resins, polycarbonate resins, polyester resins, polyamideresins, vinyl chloride resins, polyacrylate resins, polyacetal resins,polyphenylene ether resins, polyphenylene sulfide resins,fluorine-containing resins, imide resins, ketone resins, sulfone resins,urethane resins, polyvinyl acetate, polyethylene oxide, polyvinylalcohol, polyvinyl ether, polyvinyl butylal, phenoxyl resins,photosensitive resins, liquid crystal polymers, biodegradable plastics,and the like. These may be used alone or as a mixture of two or morekinds thereof.

Of the thermoplastic resins described above, the thermoplastic resinswhich are preferably used for light irradiation molding include therubber-reinforced styrene resins, the olefin resins, the acrylic resins,the polyester resins, the polyamide resins, alloy of the polyester resinand the polycarbonate resin, alloy of the rubber-reinforced styreneresin and the polycarbonate resin, alloy of the rubber-reinforcedstyrene resin and the polyester resin, and the like.

Further, the thermoplastic resin is preferably an amorphousthermoplastic resin.

As a pair of the rubber die units are formed of rubber, the coolingspeed of the thermoplastic resin is slower than that obtained in a casein which a metal molding die is used. The crystallinity of thethermoplastic resin, accordingly, may be increased while the resin iscooled, whereby the accuracy of dimension or the impact resistance ofthe molded article may be reduced. On the contrary, when the amorphousthermoplastic resin is used as the thermoplastic resin, the reduction ofthe accuracy of dimension or the impact resistance of the molded articlemay be prevented.

The thermoplastic resin may further include additives such as fibrous,particulate or sheet filler, a decorating agent such as a metallicpigment, an ultraviolet absorbing agent, an antioxidant, an ageinhibitor, an anti-static agent, a flame retardant, a weatherproofingagent, a plasticizer, a lubricant, an antibacterial agent, an agent forproviding hydrophilic property and a pale color coloring agent,depending on the objective or the use.

A pair of the rubber die units are preferably formed of transparent ortranslucent silicone rubber.

In this case, not only the rubber die units can be easily produced butalso the thermoplastic resin can be selectively heated by using lighthaving a wavelength range of 0.78 to 2 μm while the rubber die units arehardly heated.

The silicone rubber has preferably a hardness of 25 to 80, measured inaccordance with JIS-A Standard.

The light irradiation molding apparatus includes a vacuum means forvacuating a cavity, and is preferably constituted so that a pressureinside the cavity is made lower than a pressure outside a pair of therubber die units by the vacuum means to generate a suction force on apair of the rubber die units, whereby a pair of the rubber die units aremade to come close to each other when the thermoplastic resin is molten.

In addition, in the light irradiation molding method, it is preferablethat a pressure inside the cavity is made lower than a pressure outsidea pair of the rubber die units by the vacuum means for vacuating acavity to generate a suction force on a pair of the rubber die units,whereby a pair of the rubber die units are made to come close to eachother when the thermoplastic resin is molten.

In these cases, a pair of the rubber die units are easily made to comeclose to each other by the suction force (die clamping force) generatedby the vacuum means. In addition, when a pair of the rubber die unitsare made to come close to each other by utilizing the suction force, themolten thermoplastic resin can be easily spread through the whole of thecavity.

A pair of the rubber die units can be forcibly made to come close toeach other by applying an external force to a pair of the rubber dieunits, in addition of utilization of the suction force generated by thevacuum means.

A pair of the rubber die units may be constituted so that an engagingprotrusion, which is formed in one unit, is engaged with a depression tobe engaged, which is formed in the other unit, in an initial positionbefore the units are made to come close to each other, and a wholecircumference of a parting plane, which is formed between a pair of therubber die units, is closed by the engaging protrusion and thedepression to be engaged.

In this case, it is easy to prevent leakage of the thermoplastic resinfrom a gap formed on the parting plane for an approach of a pair ofrubber die units to each other.

In addition, a pair of the rubber die units may be constituted so that acavity-forming protrusion formed in one of the rubber die units isarranged in a cavity-forming depression formed in the other rubber dieunit in an initial position before the rubber die units are made to comeclose to each other, and the parting plane is entirely closed by a resintape which is pasted on an entire circumference of the parting planeformed between a pair of the rubber die units.

In this case, it can also be easy to prevent leakage of thethermoplastic resin from a gap formed on the parting plane for anapproach of a pair of the rubber die units to each other.

It is preferable that one of a pair of the rubber die units has acavity-forming protrusion which forms a reverse face of the moldedarticle, an annular engagement depression which is formed on an entirecircumference of a fringe area of the cavity-forming protrusion, and anannular outer circumference protrusion which is projected from an entirecircumference of a fringe area of the annular engagement depression; andthe other rubber die unit has a cavity-forming depression which has thecavity-forming protrusion arranged therein to form a designed face ofthe molded article, and an annular inner circumference protrusion whichis projected from an entire circumference of a fringe area of thecavity-forming depression and is engaged with an inner circumferentialsurface of the annular outer circumference protrusion and is arranged inthe annular engagement depression, wherein the cavity is continuouslyformed between an apical surface of the cavity-forming protrusion and abottom face of the cavity-forming depression, between an outercircumferential surface of the cavity-forming protrusion and an innercircumferential surface of the annular inner circumference protrusion,and between a bottom face of the annular engagement depression and anapical surface of the annular inner circumference protrusion, in aninitial position before a pair of the rubber die units are made to comeclose to each other; a suction port which opens in the apical surface ofthe cavity-forming protrusion, and suction gates which open in thebottom face of the annular engagement depression, are formed in the oneof a pair of the rubber die units; and the suction port and the suctiongates are communicated with a vacuum suction pathway for vacuating bymeans of the vacuum means.

In this case, the engagement of the inner circumferential surface of theannular outer circumference protrusion in one of a pair of the rubberdie units with the outer circumferential surface of the annular innercircumference protrusion in the other of a pair of the rubber die unitscan easily prevent leakage of the thermoplastic resin from the gap inthe parting plane formed for approach of a pair of the rubber die unitsto each other.

When the vacuum suction in the cavity is performed through the suctionport and the suction gates, a suction force can be easily generatedbetween a pair of the rubber die units, and the molten thermoplasticresin can be easily spread through the whole of the cavity.

In addition, when the particulate thermoplastic resin arranged in thecavity is molten, the excess molten thermoplastic resin, which overflowsfrom the cavity, can be introduced into the suction port.

It is preferable that the suction port also serves as an input port forthrowing the particulate thermoplastic resin into the cavity.

In this case, when the thermoplastic resin is arranged in the cavity,the particulate thermoplastic resin can be thrown through the suctionport in a condition in which a pair of the rubber die units are closed.

It is preferable to constitute a pair of the rubber die units so that apair of the rubber die units are made to come close to each other untilthe bottom face of the annular engagement depression in one of a pair ofthe rubber die units comes into contact with the apical surface of theannular inner circumference protrusion in the other of a pair of therubber die units, and the thermoplastic resin is supplied from thesurplus space formed between the bottom face of the annular engagementdepression and the apical surface of the annular inner circumferenceprotrusion to the stand-up wall space formed between the outercircumferential surface of the cavity-forming protrusion and the innercircumferential surface of the annular inner circumference protrusion soas to form the molded article.

In this case, the accuracy of dimension of the molded article to beformed can be stabilized. In addition, an excess amount of thethermoplastic resin used for molding can be decreased as much aspossible, and thus the amount of the thermoplastic resin used can bedecreased.

The suction gate has preferably a smaller fluid passage cross-sectionalarea than that of the suction port. The suction gates are preferablyformed in an open state at positions facing the bottom face of thecavity-forming depression and positions facing the annular innercircumference protrusion on the bottom face of the annular engagementdepression.

In this case, it is difficult to cause clogging of the suction gate withthe particulate thermoplastic resin, and the thermoplastic resin can bestably spread to edges of the cavity.

The opening positions of the suction gate in the bottom face of theannular engagement depression are preferably arranged at least at a pairor multiple pairs of positions facing each other through a central partin the annular shape. This can make the suction from the suction portwell-balanced in a circumferential direction.

The light irradiation molding apparatus can be constituted so that thelight irradiation means applies light on the outside surface of theother of a pair of the rubber die units, the suction gates is preventedfrom closing by melting and filling the particulate thermoplastic resinarranged in the cavity on the cavity-forming depression side first sothat the vacuum suction by the vacuum means is continued until thethermoplastic resin is filled in the whole cavity.

According to the light irradiation molding method, it is possible thatthe light emitted from the light irradiation means is applied to theoutside surface of the other of a pair of the rubber die units, thesuction gates is prevented from closing by melting and filling first theparticulate thermoplastic resin arranged in the cavity from thecavity-forming depression side first so that the vacuum suction by thevacuum means is continued until the thermoplastic resin is filled in thewhole cavity.

In these cases, the closure of the suction gates can be effectivelyprevented, and the suction force can be applied to between a pair of therubber die units until the thermoplastic resin is filled in the wholecavity.

The light irradiation molding apparatus can be constituted so that thelight irradiation means apply the light, moving partially, sequentiallyand relatively from one side of the outside surface of the other of apair of the rubber die units to the other side, and the thermoplasticresin is sequentially filled in the cavity from one side thereof to theother side.

According to the light irradiation molding method, it is possible thatthe light from the light irradiation means is applied, moving partiallyand sequentially from one side of the outside surface of the other of apair of the rubber die units to the other side, and the thermoplasticresin is sequentially filled in the cavity from one side thereof to theother side.

In these cases, the thermoplastic resin can be stably spread through thewhole of the cavity by gradual melting of the thermoplastic resin in thecavity.

EXAMPLE

Referring to drawings, Examples of the light irradiation moldingapparatus and method of the present invention will be explained below.

Example 1

A light irradiation molding apparatus 1 of this Example includes, asshown in FIG. 1, FIG. 2 and FIG. 4, a pair of rubber die units 2A and2B, which are formed of a rubber material having a property oftransmitting light X therethrough and form a cavity 20 in a facingposition to each other when the units are put together, and a lightirradiation means 4 for applying light X to particulate thermoplasticresin 6 arranged in the cavity 20 through surfaces of a pair of therubber die units 2A and 2B. The light irradiation molding apparatus 1has, as shown in FIG. 4 and FIG. 5, a structure in which a pair of therubber die units 2A and 2B are made to come close to each other toreduce the volume of the cavity 20 while the thermoplastic resin 6arranged in the cavity 20 is molten by light X emitted from the lightirradiation means 4, and a molded article 7 of the thermoplastic resin 6is formed in the cavity 20 having the reduced volume.

FIG. 1 and FIG. 2 show a state in which a pair of the rubber die units2A and 2B are arranged in an initial position P1. FIG. 4 shows a statein which a pair of the rubber die units 2A and 2B are slightly made tocome close to each other. FIG. 5 shows a state in which the moldedarticle 7 is formed at a position P2 at which a pair of the rubber dieunits 2A and 2B are made to come closest to each other.

Referring to FIG. 1 to FIG. 8, a light irradiation molding apparatus 1and a light irradiation molding method of this Example will be explainedin detail below.

A pair of rubber die units 2A and 2B are formed of transparent ortranslucent silicone rubber as a rubber material. A pair of the rubberdie units 2A and 2B can be produced by putting a master model (hand-madeoriginal product) of a molded article 7 to be formed in liquid siliconerubber, curing the silicone rubber, and taking the master model out fromthe cured silicone rubber. As a pair of the rubber die units 2A and 2Bare formed of rubber, a parting plane 205 (see FIG. 1 and FIG. 2), foropening the die when the molded article 7 is taken out after forming,can be easily and arbitrarily formed.

As the thermoplastic resin 6, particles of ABS resin, which is anamorphous, rubber-modified thermoplastic resin, are used. As thethermoplastic resin 6, particles having a particle size of 1 to 3000 μmcan be used. In addition, the particulate thermoplastic resin 6 is athermoplastic resin 6 in the state of a fine pellet having a bulkdensity of about 0.6.

As shown in FIG. 4, the light irradiation means 4 is constituted so thatlight X including a wavelength range of 0.78 to 2 μm is generated. Thelight irradiation means 4 is formed by using a halogen lamp capable ofemitting light X including a wavelength range of 0.78 to 2 μm(approximately corresponding to a wavelength range of near infraredray). As this halogen lamp, a halogen lamp having a peak of lightintensity within a wavelength range of 0.78 to 2 μm (at about 0.9 μm inthis Example) was used. The halogen lamp is formed using a light source41 and a reflector 42 which collects and reflects light X emitted fromthe light source 41.

The light irradiation molding apparatus 1 can more selectively heat thethermoplastic resin 6 arranged in the cavity 20 than a pair of therubber die units 2A and 2B formed of the silicone rubber by using thelight irradiation means 4, whereby a molded article 7 having stableaccuracy of dimension can be formed.

FIG. 7 is a graph showing transmittances of the light X in each siliconerubber of a transparent silicone rubber and a translucent siliconerubber, in which a horizontal axis shows a wavelength (nm) and avertical axis shows a transmittance (%) of the light X. From the figure,it can be seen that the light X having a wavelength of 200 to 2200 (nm)can penetrate each silicone rubber. When near infrared ray having thewavelength range described above is applied to the surfaces of therubber die units 2A and 2B formed of the silicone rubber, therefore,much of the near infrared ray can penetrate the rubber die units 2A and2B, and can be absorbed in the thermoplastic resin 6 in the cavity 2.

As shown in FIG. 1, the light irradiation molding apparatus 1 includes avacuum means 5 for vacuating in the cavity 20. The vacuum means 5 is apump connecting to a pair of the rubber die units 2A and 2B, and isconfigured to perform vacuum suction in the cavity 20 in which thethermoplastic resin 6 is arranged to make the inside of this cavity 20vacuum. As shown in FIG. 4 and FIG. 5, the light irradiation moldingapparatus 1 is constituted so that the pressure inside the cavity 20 ismade lower than the pressure outside a pair of the rubber die units 2Aand 2B to generate a suction force (die clamping force) F on a pair ofthe rubber die units 2A and 2B, whereby a pair of the rubber die units2A and 2B are made to come close to each other when the thermoplasticresin 6 is molten.

As shown in FIG. 6, the molded article 7 formed by the light irradiationmolding apparatus 1 has a body part 71 and a stand-up wall part 72 whichis formed so as to standup almost vertically or at an angle to the bodypart 71. The stand-up wall part 72 in this Example is formed so that itstands up from the whole circumference of fringe area of the body part71. In addition to this structure, the molded article 7 can be formed sothat the stand-up wall part 72 stands up almost vertically or at anangle from appropriate parts on the body part 71. In addition, themolded article 7 can also be formed by cutting a formed part 73 in asuction port 27 described below.

As shown in FIG. 1 and FIG. 2, one side rubber die unit 2A, which is oneunit of a pair of the rubber die units 2A and 2B, has a cavity-formingprotrusion 21, which forms a reverse face 702 of the molded article 7;an annular engagement depression 22, which is formed on the wholecircumference of the fringe area of the cavity-forming protrusion 21;and an annular outer circumference protrusion 23 which is formed in thestate of a protrusion on the whole circumference of the fringe area ofthe annular engagement depression 22. The other side rubber die unit 2B,which is the other of a pair of the rubber die units 2A and 2B, has acavity-forming depression 25, which arranges the cavity-formingprotrusion 21 therein and forms a designed face 701 of the moldedarticle 7, and an annular inner circumference protrusion 26, whichprotrudes from the whole circumference of the fringe area of thecavity-forming depression 25, is engaged with an inner circumferentialsurface 231 of the annular outer circumference protrusion 23 and isarranged in the annular engagement depression 22.

A depression to be engaged in the rubber die units 2A and 2B is formedby the annular engagement depression 22 and the annular outercircumference protrusion 23 in the one side rubber die unit 2A, and anengaging protrusion in the rubber die units 2A and 2B is formed by theannular inner circumference protrusion 26 in the other side rubber dieunit 2B.

An outer circumferential surface 263 of the annular inner circumferenceprotrusion 26 in the other side rubber die unit 2B is engaged with aninner circumferential surface 231 of the annular outer circumferenceprotrusion 23 in an initial position P1 before a pair of the rubber dieunits 2A and 2B are made to come close to each other. A wholecircumference of a parting plane 205, formed between a pair of therubber die units 2A and 2B, is closed by the outer circumferentialsurface 263 of the annular inner circumference protrusion 26 and theinner circumferential surface 231 of the annular outer circumferenceprotrusion 23, before and after a pair of the rubber die units 2A and 2Bare made to come close to each other.

The engagement of the inner circumferential surface 231 of the annularouter circumference protrusion 23 in the one side rubber die unit 2Awith the outer circumferential surface 263 of the annular innercircumference protrusion 26 in the other side rubber die unit can easilyprevent leakage of the molten thermoplastic resin 6B from a gap 29formed on the parting plane 205 for the approach of a pair of rubber dieunits 2A and 2B to each other.

As shown in FIG. 1 and FIG. 2, the cavity 20 is continuously formedbetween an apical surface 211 of the cavity-forming protrusion 21 and abottom face 251 of the cavity-forming depression 25, between an outercircumferential surface 212 of the cavity-forming protrusion 21 and aninner circumferential surface 262 of the annular inner circumferenceprotrusion 26, and between a bottom face 221 of the annular engagementdepression 22 and an apical surface 261 of the annular innercircumference protrusion 26, in the initial position P1 before a pair ofthe rubber die units 2A and 2B are made to come close to each other.

As shown in FIG. 4 and FIG. 5, a pair of the rubber die units 2A and 2Bare constituted so that they are made to come close to each other untilthe bottom face 221 of the annular engagement depression 22 in the oneside rubber die unit 2A comes into contact with the apical surface 261of the annular inner circumference protrusion 26 in the other siderubber die unit 2B, when the thermoplastic resin 6 arranged in thecavity 20 is molten. When a pair of the rubber die units 2A and 2B aremade to come close to each other to form the molded article 7 in thecavity 20, the thermoplastic resin 6 is supplied from a body space 201formed between the cavity-forming protrusion 21 and the cavity-formingdepression 25, and a surplus space 203 formed between the bottom face221 of the annular engagement depression 22 and the apical surface 261of the annular inner circumference protrusion 26 to a stand-up wallspace 202 formed between the outer circumferential surface 212 of thecavity-forming protrusion 21 and the inner circumferential surface 262of the annular inner circumference protrusion 26. In FIG. 4 and FIG. 5,6A shows the particulate thermoplastic resin and 6B shows the moltenthermoplastic resin.

As shown in FIG. 1 and FIG. 2, in the one side rubber die unit 2A, asuction port 27, which opens in the apical surface 211 of thecavity-forming protrusion 21, and suction gates 28, which open in thebottom face 221 of the annular engagement depression 22, are formed,which pierce the rubber die unit. The suction port 27 also has afunction as an input port for throwing the particulate thermoplasticresin 6A into the cavity 20. The suction port 27 further has a functionas a space to which the excess molten thermoplastic resin 6B overflowsfrom the body space 201, when the particulate thermoplastic resin 6Aarranged in the body space 201 is molten.

The molded article 7 formed in this Example is, as described above, anarticle in which the stand-up wall part 72 stands up almost verticallyor in an inclination state on the whole circumference of the body part71. As shown in FIG. 3, the suction gates 28 are formed in an open statein positions facing the bottom face 251 of the cavity-forming depression25 and positions facing the annular inner circumference protrusion 26 inmultiple portions on the bottom face 221 of the annular engagementdepression 22. FIG. 3 shows a state in which the suction port 27 and themultiple suction gates 28 are formed on the one side rubber die unit 2A.

The suction gates 28 can be appropriately formed in accordance with theposition at which the stand-up wall part 72 is formed.

For example, when only a pair of the stand-up wall parts 72 which faceeach other are formed, the suction gates 28 are formed in an open stateonly at positions facing the bottom face 251 of the cavity-formingdepression 25 and positions facing the annular inner circumferenceprotrusion 26 in parts where the stand-up wall parts 72 are formed inthe bottom face 221 of the annular engagement depression 22. As shown inFIG. 8, it is possible not to form the suction gates 28 at the positionsfacing the bottom face 251 of the cavity-forming depression 25 and thepositions facing the annular inner circumference protrusion 26 in aremaining part of the bottom face 221 of the annular engagementdepression 22 in which the stand-up wall parts 72 are not formed. Inthis case, the outer circumferential surface 212 of the cavity-formingprotrusion 21 in the one side rubber die unit 2A is brought into contactwith the inner circumferential surface 262 of the annular innercircumference protrusion 26 in the other side rubber die unit 2B, in theremaining part of the bottom face 221 of the annular engagementdepression 22 in which the stand-up wall parts 72 are not formed,whereby it is possible to prevent an inflow of the molten thermoplasticresin 6 into between the apical surface 261 of the annular innercircumference protrusion 26 and the bottom face 221 of the annularengagement depression 22.

As shown in FIG. 1 and FIG. 2, the suction gate 28 has smaller fluidpassage cross-sectional area than that of the suction port 27. Thesuction gate 28 is formed to have a smaller fluid passagecross-sectional area than a particle size of the thermoplastic resin 6A,so that the particulate thermoplastic resin 6A in the cavity 20 is notsucked when the gases (air) in the cavity 20 is sucked by the vacuummeans 5.

Back-up plates 3 are arranged in layers on a side of the one side rubberdie unit 2A which does not face the other side rubber die unit 2B. Avacuum suction pathway 31 for vacuating by the vacuum means 5 is formedbetween the one side rubber die unit 2A and the back-up plates 3. Thevacuum suction pathway 31 is communicated with the suction port 27 andthe multiple suction gates 28.

As shown in FIG. 4 and FIG. 5, the light irradiation means 4 is locatedso that it faces an outside surface 206 formed parallel to the bottomface 251 of the cavity-forming depression 25 in the other side rubberdie unit 2B. In the light irradiation molding apparatus 1, theparticulate thermoplastic resin 6A arranged in the cavity 20 can bemolten first from the side of the cavity-forming depression 25 byapplying the light X emitted from the light irradiation means 4 to theoutside surface 206 of the other side rubber die unit 2B. In the lightirradiation molding apparatus 1, the closure of the suction gate 28 isprevented, whereby the vacuum suction can be continued by the vacuummeans 5 until the molten thermoplastic resin 6B are filled in the wholeof the cavity 20.

FIG. 4 and FIG. 5 show a state in which the light X is applied to a pairof the rubber die units 2A and 2B, in which the one side rubber die unit2A having the suction port 27 formed is arranged below, from above theother side rubber die unit 2B by the light irradiation means 4. On thecontrary, it is possible that a pair of the rubber die units 2A and 2Bare arranged so that the one side rubber die unit 2A and the other siderubber die unit 2B are combined in a horizontal direction and the lightX is applied from a horizontal direction. The light X can also beapplied to a pair of the rubber die units 2A and 2B, in which the otherside rubber die unit 2B is arranged below, from above the one siderubber die unit 2A by the light irradiation means 4.

Next, effects obtained from the light irradiation molding method usingthe light irradiation molding apparatus 1 described above will beexplained.

First, in a step for arranging the resin, the particulate thermoplasticresin 6A is arranged in the cavity 20 formed between a pair of therubber die units 2A and 2B. At this time, the thermoplastic resin 6A canbe thrown from the suction port (input port) 27 formed in the one siderubber die unit 2A into the cavity 20 between a pair of the rubber dieunits 2A and 2B which are combined with each other. The thermoplasticresin 6A can also be arranged in the cavity-forming depression 25 in theother side rubber die unit 2B in an open state. In this case, a pair ofthe rubber die units 2A and 2B are combined with each other in the statein which the thermoplastic resin 6A is arranged.

In particular, when the solid thermoplastic resin 6 is used, it ispossible that the thermoplastic resin 6 is arranged in thecavity-forming depression 25 or the cavity-forming protrusion 21, andthen a pair of the rubber die units 2A and 2B are combined. In addition,the thermoplastic resin 6 can be used as a mixture of the particulateresin and the solid resin.

As shown in FIG. 1 and FIG. 2, in a state in which a pair of the rubberdie units 2A and 2B are combined, the whole circumference of the partingplane 205 formed between a pair of the rubber die units 2A and 2B isclosed by the inner circumferential surface 231 of the annular outercircumference protrusion 23 in the one side rubber die unit 2A and theouter circumferential surface 263 of the annular inner circumferenceprotrusion 26 in the other side rubber die unit 2B.

Subsequently, in a step for molding the resin, as shown in FIG. 1, thevacuum means 5 starts vacuum suction of inside of the cavity 20 from thevacuum suction pathway 31 through the suction port 27 and the multiplesuction gates 28. At this time, air in a gap, formed among the particlesof the thermoplastic resin 6A in the cavity 20, is sucked, and a suctionforce F is applied to a pair of the rubber die units 2A and 2B and aremade to come close to each other, whereby a pressure is applied tobetween the particles of the thermoplastic resin 6A.

Then, as shown in FIG. 4, in a state in which the vacuum suction iscontinued by the vacuum means 5, the light X having a wavelength rangeof 0.78 to 2 μm is applied to the outside surface 206 of the other siderubber die unit 2B by using the light irradiation means 4. At this time,much of the light X penetrates the other side rubber die unit 2B, and isabsorbed in the thermoplastic resin 6A in the cavity 20. Thethermoplastic resin 6A, which is located near the bottom face 251 of thecavity-forming depression 25 in the other side rubber die unit 2Barranged near the light irradiation means 4, is positively heated. Amongthe particulate thermoplastic resin 6A arranged in the cavity 20,particles, located near the bottom face 251 of the cavity-formingdepression 25 of the other side rubber die unit 2B in the body space 201of the cavity 20, are first molten.

At this time, a pressure applied to among the particles of theparticulate thermoplastic resin 6A is released by the melting of theparticulate thermoplastic resin 6A due to the vacuum state of gaps amongthe particles, and the particulate thermoplastic resin 6A in the bodyspace 201 is molten by the suction force F applied to a pair of therubber die units 2A and 2B to decrease the volume of the body space 201.This causes the approach of a pair of the rubber die units 2A and 2B toeach other by only the decreased volume of the body space 201.

After the thermoplastic resin 6A in the cavity 20 starts to be molten,the vacuum suction in the cavity 20 is continued by the vacuum means 5.

As shown in FIG. 5, the particles, located near the bottom face 251 ofthe cavity-forming depression 25 in the body space 201 of the cavity 20in the particulate thermoplastic resin 6A in the cavity 20, are firstmolten, and then the melting is sequentially moved to the particleslocated near the apical surface 211 of the cavity-forming protrusion 21.The particulate thermoplastic resin 6A arranged in the stand-up wallspace 202 and the surplus space 203 in the cavity 20 is maintained inthe particulate state without melting until almost entire particulatethermoplastic resin 6A arranged in the body space 201 is molten. Thiscauses the continuation of the vacuum suction in the body space 201 inthe cavity 20 from the gaps formed among the particles of theparticulate thermoplastic resin 6A arranged at the suction port 27 andthe multiple suction gates 28.

When the particulate thermoplastic resin 6A in the body space 201 ismolten and a pair of the rubber die units 2A and 2B are made to comeclose to each other, then the particulate thermoplastic resin 6Aarranged at the stand-up wall space 202 and the surplus space 203 ismolten. At this time, the molten thermoplastic resin 6B in the surplusspace 203 is supplied to the stand-up wall space 202 by the approach ofa pair of the rubber die units 2A and 2B to each other when the volumeof the surplus space 203 is decreased. The surplus molten thermoplasticresin 6B in the body space 201 is also supplied to the stand-up wallspace 202.

Thus, a shortage of the thermoplastic resin 6 in the stand-up wall space202 can be supplied from that in the surplus space 203 and the bodyspace 201, when the particulate thermoplastic resin 6A in the stand-upwall space 202 is molten, and it can be avoided to thin the thickness ofthe stand-up wall part 72 formed in the stand-up wall space 202. A pairof the rubber die units 2A and 2B are made to come close to each otheruntil the bottom face 221 of the annular engagement depression 22 in theone side rubber die unit 2A comes into contact with the apical surface261 of the annular inner circumference protrusion 26 in the other siderubber die unit 2B, when the thermoplastic resin 6 arranged in thecavity 20 is molten. A molded article of the thermoplastic resin isformed in the state of a thin sheet (burr) between the bottom face 221of the annular engagement depression 22 and the apical surface 261 ofthe annular inner circumference protrusion 26.

As described above, in the step for molding the resin, the vacuumsuction by the vacuum means 5 is continued until the moltenthermoplastic resin 6B is filled in the entire cavity 20, and the moltenthermoplastic resin 6B can be spread through the whole of the cavity 20having a reduced volume.

Next, in a step for cooling the resin, a state in which thethermoplastic resin 6B is filled in the cavity 20 formed by a pair ofthe rubber die units 2A and 2B is maintained. At this time, the moltenthermoplastic resin 6B is cooled to be solidified, and the body part 71is formed in the body space 201 and the stand-up wall part 7 is formedin the stand-up wall space 202, thus resulting in obtaining the moldedarticle 7 of the thermoplastic resin 6.

After that, in a step for removing the molded article, a pair of therubber die units 2A and 2B are released, and the molded article 7 can betaken out.

According to this Example, the thermoplastic resin 6 can be selectivelyheated and molten, compared to the rubber die units 2A and 2B, and thetemperature increase of the rubber die units 2A and 2B is inhibited,whereby the thermoplastic resin 6 can be effectively heated.Consequently, heat deterioration of the rubber die units 2A and 2B canbe effectively prevented, when the molded article 7 of the thermoplasticresin 6 is formed.

In addition, because the volume of the cavity 20 is reduced, therebyforming the molded article 7, it is not required to fill the moltenthermoplastic resin 6B into the cavity 20. Apparatuses such as aresin-pouring nozzle for pouring the thermoplastic resin 6, which hasbeen previously molten, into the cavity 20, are not required, either.Furthermore, almost all thermoplastic resin 6 arranged in the cavity 20can be used for forming the molded article 7.

According to the light irradiation molding apparatus 1 of this Exampleand the light irradiation molding method using the same, therefore, anapparatus for previously melting the thermoplastic resin 6 and pouringit into the cavity 20 is not required, and the molded article 7 can beformed using a small amount of the thermoplastic resin 6 used.

Example 2

In this Example, some examples having a different structure from that ofthe light irradiation molding apparatus 1 of Example 1 will be shown.

A pair of rubber die units 2A and 2B can have a structure in which, asshown in FIG. 9, a whole circumference of a parting plane 205 is closedby a resin tape 35, which is pasted on the whole circumference of theparting plane 205 formed between a pair of the rubber die units 2A and2B, in addition to a structure in which the whole circumference of theparting plane 205 between a pair of the rubber die units 2A and 2B isclosed by engagement of an inner circumferential surface 231 of anannular outer circumference protrusion 23 with an outer circumferentialsurface 263 of an annular inner circumference protrusion 26.

Specifically, a cavity-forming protrusion 210 is formed on a one siderubber die unit 2A and, at the same time, a an annular depression 220 isformed on the whole circumference of a fringe area thereof, and acavity-forming depression 250 is formed on the other side rubber dieunit 2B and, at the same time, an annular protrusion 260 is formed onthe whole circumference of a fringe area thereof.

A gap 29 formed at the parting plane 205 between the one side rubber dieunit 2A and the other side rubber die unit 2B is closed by a resin tape35, which is bridged between a side face 207 of the one side rubber dieunit 2A and a side face 207 of the other side rubber die unit 2 andpasted to them. At this time, a spacer 61 of a thermoplastic resin 6having the same composition as that of the thermoplastic resin 6 usedfor forming the molded article 7, is arranged between the bottom face ofthe annular depression 220 and the apical surface of the annularprotrusion 260. A volume of the body space 201 before molding, i.e., avolume of the cavity 20 before molding, can be adjusted to an intendedvolume by controlling the height of this spacer 61. In this case, theresin tape 35 prevents leakage of the molten thermoplastic resin 6 inthe cavity 20 into the outside through the gap 29 in the parting plane205.

As shown in FIG. 10, the light irradiation means 4 can be constituted sothat irradiation of light X is partially performed, while it is movedsequentially from one side to the other side along an outside surface206 formed parallel to a bottom face 251 of a cavity-forming depression25 in the other side rubber die unit 2B, i.e., from one side to theother side in an orthogonal direction toward a facing direction of apair of the rubber die units 2A and 2B. The thermoplastic resin 6 issequentially heated and molten from one side to the other side in thecavity 20 formed by a pair of the rubber die units 2A and 2B by applyingthe light X from the light irradiation means 4, which is sequentiallymoved, while the inside of the cavity 20 in which the thermoplasticresin 6 is arranged is vacuated by the vacuum means 5. This enables thesequential approach of a pair of the rubber die units 2A and 2B to eachother from the one side to the other side, and filling of thethermoplastic resin 6 in the entire of the cavity 20, thereby obtainingthe molded article 7. In this case, the molten thermoplastic resin 6Bcan be stably spread through the whole of the cavity 20 by gradualmelting of the particulate thermoplastic resin 6A in the cavity 20.

In this Example, the light irradiation molding apparatus 1 has the samestructures as in Example 1 except for the structures described above,and the same effects as in Example 1 can be obtained.

1. A light irradiation molding apparatus comprising: a pair of rubberdie units which are formed of a rubber material having a property oftransmitting light therethrough and form a cavity between facing sideswhich face each other, and a light irradiation means for applying lightto a particulate or solid thermoplastic resin arranged in the cavitythrough surfaces of a pair of the rubber die units, wherein a pair ofthe rubber die units are made to come close to each other to reduce avolume of the cavity while the thermoplastic resin arranged in thecavity is molten by applying the light emitted from the lightirradiation means, whereby a molded article of the thermoplastic resinis formed in the cavity having a reduced volume.
 2. The lightirradiation molding apparatus according to claim 1, comprising: a vacuummeans for vacuating the cavity, wherein a pressure in the cavity is madelower than a pressure outside a pair of the rubber die units by thevacuum means to generate a suction force on a pair of the rubber dieunits, whereby a pair of the rubber die units are made to come close toeach other when the thermoplastic resin is molten.
 3. The lightirradiation molding apparatus according to claim 1, wherein a pair ofthe rubber die units are set in an initial position by engaging anengaging protrusion formed in one of the rubber die units with adepression to be engaged formed in the other rubber die unit before apair of the rubber die units are made to come close to each other, and aparting plane formed between a pair of the rubber die units is entirelyclosed by the engaging protrusion and the depression to be engaged. 4.The light irradiation molding apparatus according to claim 1, wherein apair of the rubber die units are set in an initial position by arranginga cavity-forming protrusion formed in one of the rubber die units in acavity-forming depression formed in the other rubber die unit before apair of the rubber die units are made to come close to each other, and aparting plane formed between a pair of the rubber die units is entirelyclosed by a resin tape which is pasted to an entire circumference of theparting plane.
 5. The light irradiation molding apparatus according toclaim 1, wherein one of a pair of the rubber die units comprises acavity-forming protrusion which forms a reverse face of the moldedarticle, an annular engagement depression which is formed on an entirecircumference of a fringe area of the cavity-forming protrusion, and anannular outer circumference protrusion which is projected from an entirecircumference of a fringe area of the annular engagement depression; theother rubber die unit comprises a cavity-forming depression which hasthe cavity-forming protrusion arranged therein to form a designed faceof the molded article, and an annular inner circumference protrusionwhich is projected from an entire circumference of a fringe area of thecavity-forming depression and is engaged with an inner circumferentialsurface of an annular outer circumference protrusion so as to bearranged in the annular engagement depression; the cavity iscontinuously formed between an apical surface of the cavity-formingprotrusion and a bottom face of the cavity-forming depression, betweenan outer circumferential surface of the cavity-forming protrusion and aninner circumferential surface of the annular inner circumferenceprotrusion, and between a bottom face of the annular engagementdepression and an apical surface of the annular inner circumferenceprotrusion, in an initial position before a pair of the rubber die unitsare made to come close to each other; a suction port which opens in anapical surface of the cavity-forming protrusion, and suction gates whichopen in a bottom face of the annular engagement depression, are formedin one of a pair of the rubber die units; and the suction port and thesuction gates are communicated with a vacuum suction pathway forvacuating by means of the vacuum means.
 6. The light irradiation moldingapparatus according to claim 5, wherein the suction port further servesas an input port for throwing the particulate thermoplastic resin intothe cavity.
 7. The light irradiation molding apparatus according toclaim 5, wherein a pair of the rubber die units are made to come closeto each other until a bottom face of the annular engagement depressionin one of the rubber die units comes into contact with an apical surfaceof the annular inner circumference protrusion in the other rubber dieunit, and the thermoplastic resin is supplied from a surplus spaceformed between the bottom face of the annular engagement depression andthe apical surface of the annular inner circumference protrusion to astand-up wall space formed between the outer circumferential surface ofthe cavity-forming protrusion and the inner circumferential surface ofthe annular inner circumference protrusion so as to form the moldedarticle.
 8. The light irradiation molding apparatus according to claim5, wherein the suction gate has a smaller fluid passage cross-sectionalarea than that of the suction port, and is formed in an open state at aposition facing the bottom face of the cavity-forming depression and aposition facing the annular inner circumference protrusion on the bottomface of the annular engagement depression.
 9. The light irradiationmolding apparatus according to claim 2, wherein one of a pair of therubber die units comprises a cavity-forming protrusion which forms areverse face of the molded article, an annular engagement depressionwhich is formed on an entire circumference of a fringe area of thecavity-forming protrusion, and an annular outer circumference protrusionwhich is projected from an entire circumference of a fringe area of theannular engagement depression; the other rubber die unit comprises acavity-forming depression which has the cavity-forming protrusionarranged therein to form a designed face of the molded article, and anannular inner circumference protrusion which is projected from an entirecircumference of a fringe area of the cavity-forming depression and isengaged with an inner circumferential surface of an annular outercircumference protrusion so as to be arranged in the annular engagementdepression; the cavity is continuously formed between an apical surfaceof the cavity-forming protrusion and a bottom face of the cavity-formingdepression, between an outer circumferential surface of thecavity-forming protrusion and an inner circumferential surface of theannular inner circumference protrusion, and between a bottom face of theannular engagement depression and an apical surface of the annular innercircumference protrusion, in an initial position before a pair of therubber die units are made to come close to each other; a suction portwhich opens in an apical surface of the cavity-forming protrusion, andsuction gates which open in a bottom face of the annular engagementdepression, are formed in one of a pair of the rubber die units; thesuction port and the suction gates are communicated with a vacuumsuction pathway for vacuating by means of the vacuum means; the lightirradiation means applies light on the outside surface of the other ofthe rubber die units, and the light irradiation means prevent thesuction gate from closing by melting and filling the particulatethermoplastic resin arranged in the cavity on the cavity-formingdepression side first so that the vacuum suction by the vacuum means iscontinued until the thermoplastic resin is filled in the whole cavity.10. The light irradiation molding apparatus according to claim 1,wherein the light irradiation means apply the light, moving partially,sequentially and relatively from one side of the outside surface in theother of a pair of the rubber die units to the other side, and thethermoplastic resin is sequentially filled in the cavity from one sidethereof to the other side.
 11. A light irradiation molding methodcomprising: using a pair of rubber die units which are formed of arubber material having a property of transmitting light therethrough andform a cavity between facing sides which face each other, and a lightirradiation means for applying light to a particulate or solidthermoplastic resin arranged in the cavity through surfaces of a pair ofthe rubber die units; making a pair of the rubber die units to comeclose to each other to reduce a volume of the cavity, while thethermoplastic resin arranged in the cavity is molten by applying lightemitted from the light irradiation means; and forming a molded articleof the thermoplastic resin in the cavity having a reduced volume. 12.The light irradiation molding method according to claim 11, wherein avacuum means for vacuating the cavity is used; and a pressure inside thecavity is made lower than a pressure outside a pair of the rubber dieunits by the vacuum means to generate a suction force on a pair of therubber die units, whereby a pair of the rubber die units are made tocome close to each other when the thermoplastic resin is molten.
 13. Thelight irradiation molding method according to claim 12, wherein thelight emitted from the light irradiation means is applied to the outsidesurface of the other of a pair of the rubber die units, and the suctiongates is prevented from closing by melting and filling the particulatethermoplastic resin arranged in the cavity from the cavity-formingdepression side first so that the vacuum suction by the vacuum means iscontinued until the thermoplastic resin is filled in the whole cavity.14. The light irradiation molding method according to claim 12, whereinthe light emitted from the light irradiation means is applied, movingpartially and sequentially from one side of the outside surface of theother of the rubber die units to the other side, and the thermoplasticresin is sequentially filled in the cavity from one side thereof to theother side.
 15. The light irradiation molding apparatus according toclaim 2, wherein a pair of the rubber die units are set in an initialposition by engaging an engaging protrusion formed in one of the rubberdie units with a depression to be engaged formed in the other rubber dieunit before a pair of the rubber die units are made to come close toeach other, and that a parting plane formed between a pair of the rubberdie units is entirely closed by the engaging protrusion and thedepression to be engaged.
 16. The light irradiation molding apparatusaccording to claim 2, wherein a pair of the rubber die units are set inan initial position by arranging a cavity-forming protrusion formed inone of the rubber die units in a cavity-forming depression formed in theother rubber die unit before a pair of the rubber die units are made tocome close to each other, and a parting plane formed between a pair ofthe rubber die units is entirely closed by a resin tape which is pastedto an entire circumference of the parting plane.
 17. The lightirradiation molding apparatus according to claim 2, wherein one of apair of the rubber die units comprises a cavity-forming protrusion whichforms a reverse face of the molded article, an annular engagementdepression which is formed on an entire circumference of a fringe areaof the cavity-forming protrusion, and an annular outer circumferenceprotrusion which is projected from an entire circumference of a fringearea of the annular engagement depression; the other rubber die unitcomprises a cavity-forming depression which has the cavity-formingprotrusion arranged therein to form a designed face of the moldedarticle, and an annular inner circumference protrusion which isprojected from an entire circumference of a fringe area of thecavity-forming depression and is engaged with an inner circumferentialsurface of an annular outer circumference protrusion so as to bearranged in the annular engagement depression; the cavity iscontinuously formed between an apical surface of the cavity-formingprotrusion and a bottom face of the cavity-forming depression, betweenan outer circumferential surface of the cavity-forming protrusion and aninner circumferential surface of the annular inner circumferenceprotrusion, and between a bottom face of the annular engagementdepression and an apical surface of the annular inner circumferenceprotrusion, in an initial position before a pair of the rubber die unitsare made to come close to each other; a suction port which opens in anapical surface of the cavity-forming protrusion, and suction gates whichopen in a bottom face of the annular engagement depression, are formedin one of a pair of the rubber die units; and the suction port and thesuction gates are communicated with a vacuum suction pathway forvacuating by means of the vacuum means.